Central Nervous System Infection with Histoplasma capsulatum

Abstract

Histoplasmosis is an endemic fungal infection that may affect both immune compromised and non-immune compromised individuals. It is now recognized that the geographic range of this organism is larger than previously understood, placing more people at risk. Infection with Histoplasma capsulatum may occur after inhalation of conidia that are aerosolized from the filamentous form of the organism in the environment. Clinical syndromes typically associated with histoplasmosis include acute or chronic pneumonia, chronic cavitary pulmonary infection, or mediastinal fibrosis or lymphadenitis. Disseminated infection can also occur, in which multiple organ systems are affected. In up to 10% of cases, infection of the central nervous system (CNS) with histoplasmosis may occur with or without disseminated infection. In this review, we discuss challenges related to the diagnosis of CNS histoplasmosis and appropriate treatment strategies that can lead to successful outcomes.

Histoplasmosis of the Central Nervous System: A Case Series between 1990 and 2019 in French Guiana

“…When the CNS involvement is not known, transition from L-Amb to itraconazole, and then itraconazole interruption may be accelerated, thus leading to suboptimal treatment of the CNS infection. 6 …”

“…Whereas the relapse rate and mortality of CNS histoplasmosis used to be very high 5 —often presenting as meningitis in severely immunocompromised patients with poor compliance—antifungal therapy has transformed this universally fatal illness to a manageable condition, if diagnosed and treated early. 6 …”

Ischemic brain infarcts and vasculitis in histoplasmosis of the central nervous system: A case report and review of the literature

“…Moreover, visual disturbances in CNS histoplasmosis are rare, with an incidence below 10%, as stated in the largest multicenter retrospective study to date by Wheat et al [7] Most neurological manifestations were reported to be transient, lasting for less than one week in a quarter of the cases. Therefore, high index of suspicion and a prompt diagnosis are critical, as the CNS compromise not only increases morbidity, mortality and the risk of relapse, but also dictates a more aggressive and longer course of treatment [4] , [7] , [8] , [18] .…”

“…False positives and cross-reactions can happen with blastomycosis, paracoccidioidomycosis, cryptococcosis, and penicilliosis [24] , [25] . Additionally, fungal culture of the CSF is a lengthy and poorly sensitive process and is therefore best used as a confirmatory test rather than diagnostic [6] , [8] .…”

“…Involvement of the central nervous system (CNS) can occur as part of disseminated disease or as an isolated syndrome [6] . Additionally, CNS compromise carries particularly high mortality rates and worse outcomes, being often overlooked during the initial evaluation given its resemblance to stroke, vasculitis, meningitis of other etiologies, and difficult microbiological diagnosis [4] , [7] , [8] . CNS histoplasmosis with visual disturbances on presentation is rare, and the incidence of associated brain infarctions in the largest case series was 2% [7] , which indicates a challenging diagnosis without a high index of suspicion by the clinician.…”